Lithography systems are commonly used to transfer images from a reticle onto a workpiece (e.g. a semiconductor wafer) during semiconductor processing. A typical lithography system includes a chuck that retains the workpiece during processing. Some types of lithography systems, such as Extreme Ultraviolet (EUV) or electron-beam lithography systems require operation in a vacuum.
In an EUV or electron-beam lithography system, the workpiece can initially be clamped by the chuck when the workpiece and the chuck are at atmospheric pressure. Subsequently the workpiece and chuck can be moved to a transition chamber in which the environment around the workpiece and the chuck is transitioned to a vacuum. Next, the workpiece and chuck are moved to a processing chamber where the desired features are transferred to the workpiece.
Unfortunately, the workpiece can slip relative to the chuck during the transition from atmospheric pressure to a vacuum and/or while the features are being transferred to the workpiece. This will adversely influence the alignment of the workpiece relative to the chuck and will adversely influence the quality of the features subsequently transferred to the workpiece.